A hallmark of cancer is deregulated activation of the signal transduction pathways controlling proliferation, apoptosis, and differentiation. The signal transduction pathways culminate in activation of transcription factors (TFs), proteins that bind promoter regions of genes, thereby controlling transcription initiation. To understand the complex regulation of the signal transduction network, it is necessary to put in place technologies for assessment of numerous TFs. It is currently possible to monitor the specific changes occurring in cancer cells in the expression and function of genes and gene products at the DNA, RNA, or protein level. However, very few tools are available for examining the molecular changes at the TF level. ATTAGENE has developed a proprietary technology enabling the profiling of the transcriptional activities of multiple TFs in vivo. Based on this technology, we will develop an assay suitable for the profiling of several TFs that are critically involved in carcinogenesis, including c-Myc, E2F, p53, AP-1, NF-kB, CREB, and beta-catenin/TCF. The utility of this assay will be tested in several human cancer cell lines. Our technology allows for a comprehensive analysis of alterations in the signal transduction pathways occurring in cancer and for an identification of TFs that play a key role in a particular type or stage of cancer. The availability of this tool will advance understanding of cancer cell anatomy.